Error on an old phone, can't get the list of apps, likely a certification issue. How to solve?

4

If this is about F-Droid getting stuck and/or taking a long time on “Updating repositories” I have the same issue. I’ve tried clearing cache, force stopping the app, disabling and re-enabling repositories and restarting my device.
F-Droid 1.23.1
Android 7
Samsung SM-J730F